Introduction

This is the user guide for dip. dip is an application development and integration framework for Python and toolkits based on PyQt. It supports Python v3.5 and later.

dip encourages the development of applications based on reusable components. This applies both to the development of new components so that they can be reused in the future in a different context, and to the reuse of existing components that were developed independently of dip.

Developers can choose to use the different parts of dip as required. Unlike many frameworks dip does not require its wholesale adoption to develop an application. dip makes it easy to take an existing application and refactor it gradually to make use of dip’s features. Developers can also choose to replace different parts of dip with their own implementations. The Architecture section describes this in more detail.

The dip API is fairly stable but will not be finalized until v1.0. dip should not be considered for production applications until v1.0 is released. The Roadmap section provides details of the planned development.

Features

The current version of dip has the following features:

• a declarative type system where class attributes define the types of instance attributes that are created automatically when the class is instantiated
• the ability to define interfaces and to write adapters that allow an object to appear to implement an interface without needing to change the object itself
• the ability to specify a user interface declaratively. When combined with the type system it is possible to create a user interface that allows the user to edit a data model with a single line of code
• a default user interface shell that implements the menu hierarchies, context menus, toolbars etc. common to many applications
• support for user settings including, if enabled, the automatic saving and restoration of the geometry and configuration of a user interface
• dip’s user interfaces are testable because a user’s actions can be simulated programatically
• a framework for defining types of storage and data formats for reading and writing application objects
• support for alternative toolkits. This does not mean that any toolkit can be supported - a toolkit must be based on Qt. It does mean that an application can automatically use, for example, KDE widgets rather than the corresponding Qt widgets if they are available
• a plugin system that encourages the decoupling, and easy reuse, of components through the use of services and extension points
• the dip-builder utility that is be used to create a stub application that can be run immediately, and can create a packaged version of the application for easy deployment. (At the moment only distutils is supported.)
• the dip-automate utility that is used to automate the user’s interaction with any PyQt application without requiring changes to the application itself.

License

Like PyQt, dip is available under two licenses: the GPL (both v2 and v3), and the Riverbank Commercial License. Dual licensing is based on the principle of quid pro quo - something for something.

If you, your company or your organisation derive commercial benefit from Riverbank’s products and do not wish to distribute your complete source code you are required to purchase the appropriate number of commercial licenses.

Alternatively, if you are willing to follow the terms of the GPL, Riverbank software is available to you under Open Source licenses which allows you to develop, modify and distribute your software freely. If you wish to use an open source version of Riverbank’s products, you must contribute all your source code to the open source community, according to the terms of the applicable open source license.

By offering both open source and commercial licenses, Riverbank ensures the availability of resources for ongoing development and improvement of its products. By purchasing commercial licenses, you are no longer obligated to publish your source code.

Installation

dip is provided as a source packages created by Python’s distutils module. After unpacking the .tar.gz or .zip file run following command:

python setup.py install

If you want to run the tests then change to the test directory and run the following command:

python runtests.py

If you want to re-create the documentation then change to the doc directory and run the following command:

make html

dip is also available as a Mercurial repository.